* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    max-width: 800px;
    width: 100%;
    background: white;
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    padding: 60px 40px;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 20px;
    color: #2d3748;
    text-align: center;
}

.subtitle {
    text-align: center;
    color: #718096;
    font-size: 1.1rem;
    margin-bottom: 50px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.presentations {
    display: grid;
    gap: 25px;
}

.presentation-card {
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    padding: 30px;
    transition: all 0.3s ease;
    text-decoration: none;
    color: inherit;
    display: block;
}

.presentation-card:hover {
    border-color: #667eea;
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.2);
    transform: translateY(-3px);
}

.presentation-card h2 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: #667eea;
}

.presentation-card .meta {
    color: #718096;
    font-size: 0.9rem;
    margin-bottom: 15px;
}

.presentation-card .description {
    color: #4a5568;
    line-height: 1.7;
}

footer {
    margin-top: 60px;
    text-align: center;
    color: #a0aec0;
    font-size: 0.9rem;
}

footer a {
    color: #667eea;
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

@media (max-width: 640px) {
    .container {
        padding: 40px 25px;
    }

    h1 {
        font-size: 2rem;
    }

    .presentation-card {
        padding: 20px;
    }
}